Ultrasonic Transducer and Method of Operating an Ultrasonic Transducer

Abstract

In an embodiment an ultrasonic transducer includes an ultrasonic unit with a housing in which a piezoelectric element is located, wherein the ultrasonic unit includes at least one electrical connecting lead leading out of the housing, the connecting lead being configured for connection to control and/or evaluation electronics arranged separately from the ultrasonic unit, and wherein the ultrasonic unit is configured to operate in a thickness oscillation mode.

1 - 21 . (canceled) 
     
     
         22 . An ultrasonic transducer comprising:
 an ultrasonic unit with a housing in which a piezoelectric element is located,   wherein the ultrasonic unit comprises at least one electrical connecting lead leading out of the housing, the connecting lead being configured for connection to control and/or evaluation electronics arranged separately from the ultrasonic unit, and   wherein the ultrasonic unit is configured to operate in a thickness oscillation mode.   
     
     
         23 . The ultrasonic transducer according to  claim 22 , wherein the piezoelectric element is fastened to a cover plate of the housing and the ultrasonic unit is configured for operation in the thickness oscillation mode in resonance of a system of the piezoelectric element and the cover plate. 
     
     
         24 . The ultrasonic transducer according to  claim 22 , wherein the housing comprises a cover plate, wherein the piezoelectric element is fastened to the cover plate, and wherein the connecting lead is led laterally out of the housing. 
     
     
         25 . The ultrasonic transducer according to  claim 22 , wherein the housing has a disc-shaped outer geometry. 
     
     
         26 . The ultrasonic transducer according to  claim 22 , wherein the ultrasonic unit is at most twice as thick as the piezoelectric element. 
     
     
         27 . The ultrasonic transducer according to  claim 22 , wherein the connecting lead is a coaxial cable. 
     
     
         28 . The ultrasonic transducer according to  claim 22 , wherein the piezoelectric element is fastened to a cover plate of the housing, which is configured to conduct a thickness vibration of the piezoelectric element to an outside. 
     
     
         29 . The ultrasonic transducer according to  claim 22 , wherein the housing comprises a cover plate, and wherein the cover plate is a steel plate. 
     
     
         30 . The ultrasonic transducer according to  claim 22 , wherein the housing comprises a cover plate, wherein a thickness of the piezoelectric element and a thickness of the cover plate are such that they are configured to generate a vibration in a thickness-resonance at a specified operating frequency in a range of 500 kHz to 3 MHz. 
     
     
         31 . The ultrasonic transducer according to  claim 22 , wherein the housing comprises a cover plate, and wherein a thickness of the piezoelectric element is greater than a thickness of the cover plate. 
     
     
         32 . The ultrasonic transducer according to  claim 22 , wherein the ultrasonic unit has a thickness of at most 5 mm and a diameter of at most 5 cm. 
     
     
         33 . A method for operating the ultrasonic transducer according to  claim 22 , the method comprising:
 measuring a level of a liquid in a container.   
     
     
         34 . An arrangement comprising:
 the ultrasonic transducer according to  claim 22 ; and   a container,   wherein the ultrasonic unit is arranged on an underside of the container.   
     
     
         35 . The arrangement according to  claim 34 , wherein the control and/or evaluation electronics are connected to the connecting lead, and wherein the control and/or evaluation electronics are a compact electronics unit and are arranged on a side surface of the container. 
     
     
         36 . The arrangement according to  claim 34 , wherein the ultrasonic unit is fastened to the container by an adhesive or an adhesive tape. 
     
     
         37 . The arrangement according to  claim 34 , wherein the ultrasonic unit is fixed in a position solely by a weight of the container. 
     
     
         38 . A method for operating the ultrasonic transducer according to  claim 22 , the method comprising:
 operating the ultrasonic transducer in the thickness oscillation mode.   
     
     
         39 . The method according to  claim 38 , wherein the piezoelectric element is fastened to a cover plate of the housing, and wherein the ultrasonic transducer is operated in resonance of a system of the piezoelectric element and the cover plate. 
     
     
         40 . The method according to  claim 38 , wherein the ultrasonic transducer is operated at a frequency in a range of 500 kHz to 3 MHz. 
     
     
         41 . method for manufacturing an ultrasonic unit, the method comprising:
 specifying an operating frequency;   providing a piezoelectric element with a thickness for operating in a thickness vibration mode;   fastening the piezoelectric element to a cover plate; and   varying a thickness of the cover plate until the thickness vibration in resonance is obtained at the specified operating frequency.   
     
     
         42 . The method according to  claim 41 , wherein the thickness of the cover plate is varied until a thickness vibration in resonance of a system of the piezoelectric element and the cover plate is obtained at the specified operating frequency.